As an ultrasonic probe utilized in ultrasonic diagnostic apparatuses, there is an array-type ultrasonic probe in which a plurality of ultrasonic transducers are arrayed. Recently, in particular, a two-dimensional array probe makes its market debut, in which a plurality of ultrasonic transducers is two-dimensionally arrayed, allowing three-dimensional scanning for a diagnostic target region of an object.
In an ultrasonic probe having a huge number of ultrasonic transducers (i.e., the number of channels) typified by such a two-dimensional array probe, the number of wiring required for transmission and reception between the ultrasonic probe and the body of the ultrasonic diagnostic apparatus is also apt to be a huge number. This may consequently lead to a large-sized ultrasonic probe and a reduction in cable-operability.
To prevent such a problem, a means is provided so that at least part of electronic circuits for executing ultrasonic transmission and reception is provided, as ASICs (Application Specific Integrated circuits), in an ultrasonic probe, not in an ultrasonic diagnostic apparatus, and after generating a drive signal, or making the number of received signals in a predetermined signal number, in the ultrasonic probe, these signals are then sent to the ultrasonic diagnostic apparatus body. In this case, to miniaturize the ultrasonic probe, there may be a case where the ASIC is provided as a bare chip. (In general, an ASIC is encapsulated in a package, such as plastic, and the package is mounted on the board. The wording “an ASIC as a bare chip” means an ASIC in a state of being free from such a package. By mounting an ASIC as a bare chip on a board, for example, miniaturization by one package can be realized.)
However, if an ASIC is provided in an ultrasonic probe, there is a need to diffuse a quantity of heat generated by the ASIC. If the ASIC provided in the probe is a bare chip, the diffusion of the quantity of heat generated by the ASIC is a further significant technical problem. In order to efficiently diffuse the quantity of heat generated by such an ASIC and a quantity of heat generated by each ultrasonic transducer, conventional ultrasonic probes adopt methods such as using a cooling medium to aggressively cool heat (active cooling method), or a method of diffusing heat by contacting a heat conductive member with the heat source without using a cooling medium (passive cooling method).